Games racket



Patented Oct. 9, 1928.

UNITED STATES PATENT oFFlcE.

CLAUDE ALBERT cLAnEVMoNT, or Ro'ssLYN HILL, HAMPSTEAD, ENGLAND.

i GAMES RACKET.

Application filed December 9, 1927, Serial No, 238,920, and inrGreat Britain September 25, .1926.'

This invention relates to rackets for games such as tennis, badminton, etc. Rackets are usually made with a Wooden rim and 'strung with gut, but rackets are also made With metal rims,`and also With strings made of metal Wire.

The Wire-Stringing has certain advantages ther object is to eilect an improvement inr gut-strung rackets, or rackets strung in other Ways. Y

Hitherto in all rackets heretofore made the desired resiliency has been sought to be obtained from the strings and the method of stringing has been such as to inhibit distortion of the rimin the plane of the racket. This invention is based on a new principle and seeks to obtain the desired resiliency Wholly or partly by means of distortion of` an elastic rim in the plane vof the blade.

Hence the invention consists in the combination of a particular method of stringing hereinafter explained, and a rim pliable in the planeof the racket.V

Accordingly in this invention rthe rim is made ot any suitable material including-steel and Wood capable of yielding to therequired extent under applied force, in the plane ofl the racket. In the case ot Stringing of steel Wires or other comparatively nonstretchable material and in a less degree in the case of gut Stringing, to obtain resiliency reliance is placed on a distortion of the rim in the said plane against the reaction of its own 4 elasticity.

In the case of a stringing made ofgut orV other material aii'ording resiliency, the resilient rim apart from the purpose of affording resiliency is useful for the purpose of permanently maintaining thel desired tension of the gut.

The rim may be of various cross-section shapesconsistent Withy obtaining the desired resilience and affording the required strength* and Weight.

It will be realized that tofobtain resiliency from the pliability ot the rim'inthe plane of the blade necessitates that the rimvshall contract along one Aor Vmore predetermined `V areas of the blade of the racket Where it Would be immaterial) shall not be increased by Ythe predetermined permitted distortions of the rim, as each string Whose points ofV attachment violate. this conditionwould inhibit A the desired distortion.

Although it might be determined to so construct the Stringing that the rim would contract on any one or -more diameters, With consequential extensions in other directions, ior the purpose of facilitating the elucidation of this invention, so far as concerns the Stringing, I propose to describe the method' of Stringing in reference to a quasilelliptical blade, the longest diameter being in line WithA the handle, and on the basis that the resil y iency is to. be attained by a contraction of the longest diameter `With consequential extension of the shortest diameter. l

Ot course, one set of strings more or y.less parallel tothe longest diameter covering the Whole area of the blade ot the racketfwould meet the required'condition, but it is essential, in order to secure other required qualities pot a racket, that one set of strings shall crossy (and perhaps interlace With) another set, and if another set were arranged across and normal to such aset as above described,'the points of attachment of the second set Would violate the condition.

It will be realized that, many strings not i parallel tothe diameter'vof contraction would meet the said condition as to the dis? tance of the-points of attachment, and that certain strings crossing and at an angle to the longest diameter, and connecting-i points Within a limited arc from the endsl of the longest diameter would meet the said condition. yIf however 'thel Whole facel ofthe considering string e. f. in the diagram as one racket were strung with strings parallel to such strings, some oi the strings would 'tor a` certain area of the blade remote from the centra-and to a greater extent the more mote from the centre, fail to comply with the said condition. i

l rllhe strings can bearranged to attain the said condition for all practical purposes,by departing from the parallel relationship oi the strings et each set, and arranging thein to an extent tan-wise, the degree oi" divergence from the parallel depending very much on the shape oit rim adopted, the nature of the distortion permitted, andthe mag itude of the inclination oi" the main body ot strings to the diameter of contraction rilhe degree of divergence need not be constant throughout the Stringing and can even reverse in direction from sideto sido oi" the set ot strings. f

The method of ascertaining the points oi attachment of each string is shown by reiterence to the accompanying drawings in which, Fig. l is a, plan view of a rachet embodying my invention and Fig. 2 is a diagrammatic view illustrating the mode and etlect of Stringing the racket. i

a is the handle, Z; is the inside edge ot the trame in what may be called its normal position. c is the position oit the same edg after it has undergone distortion. v

rlhe lines marked CZ join points on line Z9 to the new positions oic such points, when the racket frame is distorted to the position c. i

The drawing of these two positions having been obtained a position for each string is found4 with a divider or other convenient measuring instrument, such that its two eX- tremities are either closer together when the frame is in position c, than when it is in position or remain the same distance apart in the two positions. In the diagram shown it will be found by measurement that all the strings correspond to the above condition. Thepositions shown are not the only ones which the several strings could occupy. It will be realized that given vthe lower end oi astring. f. as fixed, they upper end could lie anywhere in a certain Zone without failing to comply with the condition. For example,

of a set which have to cross a corresponding set from the other side it theend 7 be fixed thel position of the end e can bel anywhere between the points x and y witho ut violating the condition; further as the point e approaches the point jz/ the change in the length ot'the line e. f. produced by al given amount oidistortion gradually decreases, until the critical `position y is reached in which the diminution in the length of e. f. is Zero and beyond this it changes to :an incieasei The moreiiearly e approaches this critical position the greater force will have to be applied at right angles to the string to produce a given amount of distortion. It similar principles be applied in choosing the position of every such string a combination may be made in which the strings severally approach as nearly as is desired to the critical position which exists for each one, as just described inV the case ot-e.V f. Thus the method of stringing in combination with a rim pliable in the plane ot the rim can produce the desired resiliency of theracliet..

The racket rim in Vits normall position, i. e. after stringing, may or may not be in a state olf `strain due to a preliminary distortion maintained by the initial tension of the strings. l v y In some cases itkmay be in order toatt-ain a predetermined resiliency in the racket to place certain strings in violation to `the said lcondition thereby opposing and tofa degree limiting distortion, without inhibiting it altogether. lt may be observed that in some Y instances certain ot the strings will be under less strainthan others, owing to the 'fact that their relationrto the rim is such that while one end remains iXed the other end will respond to the impact et a ball against the racket bya slight movement in the arc of a circle. `This may happen especially with short strings located near the handle of the racket, but this movement does not. aliieet the action o the-racket. V

What I claim is l. A games racket 'characterized in that the rim is i'esiliently pliable in the plane of the racket, to afford the required resiliency when the blade is struck by a ball, yand the stringing isarranged not to oppose the yielding of the rim to attain such resiliency, the required resiliency being afforded wholly by the resilient pliability of the rim, the strings being ofl comparatively non-stretchable material.

2. A games racket characterized in that the rim is resilient-ly pliable, and the strings are stretchedbetween such points that on a contraction ol' one orl more predetermined diameters and consequential extension. ot' one or more other diameters, the distances'between the points olf-attachment of each stringere not increased. y

3. A games kracket characterized in that the rim is resiliently pliable inthe plane of the racket and the maj orityv of the strings are stretched between such points that on a contraction of one or more diameters of the rim,

the result of a blow on the blade as of a ball'V and consequential extension on yone or more other diameters the distances between the points of attachments of each such, stringf are not more distant, while oneor more ot the reinainingstrings are arranged to oppose the distortion of the rim. f 4. As a process in thel making of va racket in which the rimis-resiliently pliablefin the plane ot' the blade, and the Stringing does not oppose the required resiliency of the racket from being obtained from distortion of the rim, ascertaining the points of attachment of some or all ofthe strings by distorting va rim by means of pressure along a diameter, making` a drawing in which the rim under normal tension, and the rim asso ldistorted are superimposed, determining therefrom the pointsof attachment so that in reference to some or all of therstrings the points of attachment are not more distant When the rim isY distorted 10 than when in normal position and Stringing the rim accordingly.

In Witness i whereof I have Signed this specification.

CLAUDE ALBERT 'oLAREMoNT.- 

